A pair of precociously charming perfs and a gritty sense of street can't prevent "The Inevitable Defeat of Mister and Pete" from wading into soggy sentiment.

A pair of precociously charming perfs and a gritty sense of street can’t prevent “The Inevitable Defeat of Mister and Pete” from wading into soggy sentiment. Why it stays there so long is another issue, although helmer George Tillman Jr. doesn’t have a solid story in Michael Starrbury’s script: Once the film’s preteen heroes are abandoned by their mothers in their Brooklyn housing project, the pic simply moves from one strife-filled episode to another. Cast names could attract midrange biz, as could the spunky young characters, although it’s a lot of misery for too little objective.

At the center of the film is the oddly named Mister (a terrific young Skylan Brooks), who’s failing at school and about to repeat the eighth grade. In his agitation, he lashes out at his teacher; at his mother, Gloria (Jennifer Hudson), a hopeless junkie who turns tricks in diner toilets; and at Pete (Ethan Dizon), the oddly polite neighbor kid whose mother is also a hooker/junkie, working for Kris (Anthony Mackie, in a virtual cameo).

Mister’s school problems are presumably the catalyst for his rebellion, at this particular moment, against the only life he’s ever known. But Tillman’s choice, to open the film at a moment of crisis — rather than first immersing the audience in the drugs-and-guns-filled housing project where the story is set — results in Mister seeming as much of a stranger to this world as the viewer is.

Another mystery: Why is the very proper Pete so different from the vulgarity-spewing Mister, given that they’re both the sons of drug-using hookers? In the logic of the film, it must be because he’s Korean.

Mister hasn’t gotten much support from Gloria, but when she’s picked up in a police raid, he’s really alone, and finds himself saddled with Pete. How will they eat? How will they elude the police — notably a persistent sergeant (Adewale Akinnuoye-Agbaje), who knows they’re holed up in Gloria’s apartment? There’s a certain amount of tension generated by the vulnerability of the two boys, the predatory nature of so much of their surroundings, and their often harrowing encounters (few movies feature female child molesters, but this is one of them). But nothing’s very convincing for very long.

Mister, a would-be actor, dreams of attending an upcoming open-call for a Los Angeles-based TV show and being whisked away from his ugly reality. “The Inevitable Defeat of Mister and Pete” doesn’t really develop this idea, or any others, because it’s too busy skipping from mishap to mishap. At one point during the boys’ weeks alone, Mister runs through a series of impressions to entertain Pete; they include Will Smith in “Men in Black” and a pretty impressive Steve Buscemi from “Fargo.” It’s a clever bit, but the unavoidable sense is that the movie is just killing time en route to an inevitable outcome.

Tech credits are fine, augmented by a score devised by Mark Isham and Alicia Keys, one of the film’s exec producers.